CES, the biggest tech convention in the world, is under fire for the lack of female speakers at this year’s event on January 12, 2018, and last year’s CES. You have to go back to 2016 to find women keynote speakers: General Motors CEO Mary Barra and IBM CEO Ginny Rometty. 2015 was also an all-male lineup, but 2014 had Yahoo CEO Marissa Mayer making one of the top speeches.

That lack of diversity has outraged the Gender Avenger, a group that “ensures women are represented in the public dialogue,” per its mission statement. On November 29, the organization published an “action alert” noting that the six top speaker spots are reserved for men–such as Intel CEO Brian Krzanich and Huawei CEO Richard Yu. “You still have over 5 weeks to make this right, CES,” read the last line of the alert–a challenge to the Consumer Technology Association (CTA), which puts on the show.

People with big job titles–especially in marketing–are starting to notice. Twitter CMO Leslie Berland tweeted, “Hey @CES. Big respect for what you’ve built. Please do better here. I’ve got a long list of amazing women to hit your stage. Let’s talk. #changetheratio.” HP’s global CMO Antonio Lucio jumped on that thread and took it to 11. “All men should boycott @CES if women are not invited to speak!” he wrote. Others calling out CES include former PepsiCo Global president Brad Jakeman, Twitter director of sales Robin Wheeler, and ToysRUs global CMO Carla Hassan.

Karen Chupka, the SVP for CES & corporate business strategy at CTA, weighed in for the show’s organizers. “We go beyond the keynote stage & bring a diversity of speakers to all our conference programming,” she tweeted. Her post included photos of six prominent women who have spoken at CES in the past (not necessarily in keynotes), including Barra, Rometty, and Mayer.

@CES has a long tradition of diverse keynoters highlighting the latest in technology. We go beyond the keynote stage & bring a diversity of speakers to all our conference programming and we encourage you to check out our past CES lineups. Diversity is too important to ignore. pic.twitter.com/E431on92mK